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What kind of particles does the emitter create in a smoke alarm?
Wiki User
∙ 11y ago
Smoke alarms typically use photo-electric sensors or alpha-particle emitters, although the photo-electric sensors are much better for detecting smoldering fires.
Wiki User
∙ 11y ago
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How a fire alarm would be raised?
The fire alarm device is usually equipped with an Amercium-241 that is alpha emitter source together with a battery derived electric circuit. In the normal situation the alpha particles ionize the air causing circuit connection. However when there is a smoke the circuit is disconnected due to the smoke that acts as an insulator and hence the alarm is actuated.
Will incense set off a smoke alarm?
Any type of smoke, steam or particles denser than air will set off a smoke alarm. This means that smoke emitted from the incense will set off a smoke alarm when in range of the detector.
What is a function of a transistor in a fire alarm circuit?
A special sensor or transducer called a thermistor is used to detect an increase in the temperature of the surrounding air whenever smoke is produced by a fire. A different type of sensor is used to detect an increase in the size and density of particles in the surrounding air after it has been contaminated by smoke from a fire. Either sensor gives an output in the form of an increase in voltage whenever it detects an increased temperature and/or smoke particles. That increase in voltage is fed to the base of a transistor. When the voltage to its base increases, the current from the transistor's emitter to collector (or from its collector to emitter) increases and that increase in current operates the alarm. In other words, in a fire alarm circuit, the transistor acts as a switch which turns on the alarm whenever a sensor or transducer detects the presence of a fire, else it remains off.
How are alpha particles used in smoke alarms?
Alpha radiation is emitted from the amercium button in a smoke detector. When smoke goes into the smoke detector it blocks the stream of alpha particles emitted from the americium. That triggers an alarm.
How is radioactivity used in smoke detectors?
There are two types of smoke detectors:Photoelectric Smoke detectorsIonizing Smoke DetectorsIonization smoke detectors are more commonly used. The smoke detector uses an ionization chamber and a source of ionizing radiation to detect smoke.Alpha particles are emitted from from the chamber, which ionize the air, so that the air conducts electricity and a small current flows.If smoke enters the alarm, it absorbs the alpha particles causing the current to reduce, and the alarm sounds.Generally, smoke detectors use a weak source made of Americium-241 (241Am95).Note: Alpha particles are the nuclei of a Helium Atom (4He2).
Why does your smoke alarm suddenly flash a white light intermittently?
when alpha particles are accelerated between the electrified parallel plates, a few electrons of charged particles are energised and then eject a flash of light on return to original energy level. the probability of this happening is random due to the narrow conditions necessary for such phenomenon. ionising smoke detectors have a small [1 micro curie alpha source] that ejects alpha particles into an electric field. if the flow of alpha particles is prevented [by smoke particles], an alarm is sounded.
Where would you not install a smoke alarm?
I would not install a smoke alarm, in the kitchen.
What are smoke particles?
smoke is a suspenison of what particles ?
What is smoke detectors?
really old rapter
How Do smoke alarm Work?
There are 2 types of smoke detectors: ionization detectors and photoelectric detectors. Although they use different mechanisms both essential set off an alarm when smoke obscures the line of sight between 2 objects within the detector.
What is bigger gas particles or smoke particles?
smoke particles are bigger than gas particles.
Describe how smoke detectors use alpha particles and what sets off the alarm?
Alpha particles constantly released by americium knock electrons off atoms in the air ionizing the oxygen, nitrogen atoms
